82. Even the most deserving mediums are not exempt from manifestations by deceitful spirits; first, because none are sufficiently perfect not to have a weak spot that can provide access to evil spirits; second, in order to exercise their judgment, good spirits at times allow it to happen so that their mediums can learn how to tell truth from error and be wary so as not to accept anything blindly without having tested it first. But deception does not come from good spirits and any respectable name that signs an error is necessarily apocryphal.
This may also be a test of patience and perseverance for any Spiritist, medium or not. Those who become discouraged by a few deceptions show good spirits that the latter cannot count on them.